This application is a Continuation of PCT International Application No. PCT/F199/00409 filed on May 12, 1999, which designated the United States and on which priority is claimed under 35 U.S.C. xc2xa7 120, the entire contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to an arrangement for guiding the car cable of an elevator.
2. Description of the Related Art
An elevator car is connected to the outside space via a car cable, which is used for the supply of electricity to the elevator car and transmission of data between the car signal equipment, such as display devices and call buttons, and the elevator control system. One end of the car cable is attached to a suitable place in the elevator shaft and the other is connected to the bottom of the elevator car or car frame. The car cable hangs in the elevator shaft either freely or, in taller buildings, loaded with a tensioning weight.
In high-rise buildings, the elevator shaft may be hundreds of meters long, so the car cable may have a length of tens of meters and it tends to swing in spite of the tensioning weight. In a tall building, swinging is generated by the movements of the elevator and the resulting air currents and by the sway of the building. In elevators mounted in ships, the elevator shaft is not always upright due to the pitching and rolling motion of the ship, which causes swinging of the car cable. In elevators mounted on the outside of a building, the elevator shaft is partly exposed to ambient conditions, permitting the wind to seize the relatively light car cable.
A swinging car cable may get stuck on structural parts of the elevator shaft or it may hit the shaft walls, resulting in damage to the cable or possibly even to shaft equipment. A swinging car cable hitting other objects also generates unpleasant noise.
Finnish patent FI C 91740 presents an apparatus in which the car cable is held fast on a shaft wall by using pressurised air. However, this solution requires a car cable suited for the purpose and special pneumatic equipment in the elevator shaft along the whole length of the cable. The solution is expensive and difficult to maintain.
The object of the present invention is to produce an advantageous solution to the problem described above and to develop a car cable guide apparatus which reliably prevents excessive cable car swing.
In the solution of the invention, the free portion of the car cable, i.e. the portion between the elevator car and the fixed attachment point, is tied to at least one cable holder, thus preventing lateral swing of the cable. The car cable is automatically engaged and released by the holders as the cable loop below the car is ascending or descending in the shaft. The engagement and release of the cable is preferably achieved by using a tensioning weight system comprised in the cable equipment.
Further scope of the applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.